• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.605-612
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• 2008

The shear wave velocity ($V_s$) has been commonly used to evaluate the dynamic properties of soil. The field $V_s$ probe (FVP) was already developed to assess the shear stiffness of a soft clay. The objective of this study is to investigate the disturbance effects of the FVP due to the penetration. The laboratory tests are conducted in a large-scale consolidometer (calibration chamber). The reconstituted clay is mixed at the water content of 110% using a slurry mixer. The FVP and down-hole test are carried out every 1cm interval to compare the data. In addition, two square rods with transducers are also implemented to get the reference value. The shear waves evaluated by the FVP, dow-hole tests, and reference rods are closely matched. This study suggests that the disturbance effect of the FVP due to the penetration into the soft clay soils is small enough and the $V_s$ evaluated by the FVP reflects well the in-situ characteristics. Furthermore, the combination of the FVP and down-hole test shows the possibility of hybrid equipment.

• Journal of the Korean Society of Propulsion Engineers
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• 제15권1호
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• pp.35-44
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• 2011

Mathematical modelling for liquid rocket engine(LRE) main components were conducted to predict the dynamic characteristics when the LRE operates at the transient condition, which include engine start up, shut down, or thrust control. Propellant feeding system is composed of fuel and oxidizer feeding components except for regenerative cooling channel for the fuel circuit. Components modeling of pump, pipe, orifice, control valve, regenerative cooling channel and injector was serially made. Hydraulic tests of scale down component were made in order to validate modelling components. The mathematical models of engine components were integrated into LRE transient simulation program in concomitant with experimental validation.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.89-94
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• 2003

The formation of a severe snow storm occurred in the mountainous coastal region near Mt. Taegualyang and Kangnung city in the eastern part of Korea was investigate from 0900LST, December 7 through 9, 2002, using MM5 model. As synoptic scale easterly wind induced a great amount of moisture from the East Sea into the inland coastal region and sea-breeze further induced more moisture from the basin toward the top of the mountain side. The lifted moisture toward the mountain top was cooled down along the eastern slope of the mountain and near the mid of the mountain the moisture was much cooled down with relative humidity of 100％ under the air temperature below $O^{\circ}C$, resulting in the formation of snow. Relative humidity of 100％ generally occurred at the 5km away from the coast toward the inland mountain and the band of 100％ RH was parallel to the coastal line. The 100％ band coincided with minimum air temperature band and line.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2004년도 학술대회지
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• pp.1-6
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• 2004

We ensure a flat and regular basic surface by using part of joint waterproofing improved sheet method applying the upper slab of a concrete structure. We solve the problem of getting loose scale the general sheet by waterproofing of the sheet and improving adhesive strength of the basic concrete. Also, waterproofing sheet union to problem of joint have solved using of insertion type method so that, it improved a watertightness. It has improved in resist impact, resist abrasion and it is the effect of shortened construction period and cutting down on construction expenses. Here are the special quality and superiority of this waterproofing research. (1) Level material has the super adhesive strength so that it makes the basic surface without the gab of waterproofing sheet and waterproofing layer with the string adhesive strength. (2) We unite the sheet with the joining part between sheets by waterproofing sheet joint using of method. (3) There is the effect of shortened construction period and cutting down on construction expenses without waterproofing of protection.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.705-706
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• 2008

When heat generated inside a large factory building is not discharged due to a stagnant flow, the working environment of workers becomes worse and the cooling of high-temperature products such as hot-rolling coils is delayed. To investigate the natural ventilation inside a large factory building, experimental studies were carried out using wind-tunnel tests. The scale-down factory building models were placed in an atmospheric boundary layer (ABL) and the mean and fluctuating velocity fields were measured using a particle image velocimetry (PIV) technique. For the prototype factory model, the outdoor air is only entrained into the factory building through the one-third open windward wall, and stagnant flow is formed in the rear part of the target area. In order to improve the indoor ventilation environment of the factory building, three different louver-type ventilators were attached at the upper one-third open windward wall of the factory model. Among the three louver ventilators tested in this study, the ventilator model #3 with the outer louver (${\theta}_o$ = 90$^{\circ}$) and the inner louver (${\theta}_i$ = -70$^{\circ}$) was found to improve the natural ventilation inside the factory building model effectively. The flow rate of the entrained air was increased with aligning the outer louver blades with the oncoming wind and guiding the entrained air down to the ground surface with elongated inner louver blades.

• International Commerce and Information Review
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• 제10권2호
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• pp.45-62
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• 2008

As the Internet settles down as a general means, every year the domestic e-commerce transaction using the internet rapidly increases in its scale, and the conflicts occurred from the e-commerce largely grow as well. However, it is true that the clear settlement means to work out such conflicts is not established yet. Considering the feature of e-commerce, it would be better to resolve them by ADR rather than by lawsuits in the court, and in addition to it, the ODR system having sweetness as its advantage will be the optimized model. But to make the ODR settled down, there are many assignments to be improved in many aspects afterwards. In case of our country also, since the ODR system is still its early developing step, it is not activized yet due to its weak technical, lawful environments. Thus, currently, it is unavoidable to operate the dispute mediation system, carrying out a system by the existing Off-line together, and thereby, as we replace the parts worked out by the Off-line with by the On-line, we must try to develop it into a quick, cheap, and reliable dispute settlement system.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.430.1-430.1
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• 2014

According to advanced nanotechnology in the field of biomedical engineering, many studies of the interaction between topography of surfaces and cellular responses have been focused on nanostructure. In order to investigate this interaction, it is essential to make well-controlled nanostructures. Electron beam lithography (EBL) have been considered the most typical processes to fabricate and control nano-scale patterns. In this work, $TiO_2$ nanowire array was fabricated with hybrid process (top-down and bottom-up processes). Nanodot arrays were patterned on the substrate by EBL process (top-down). In order to control the spacing between nanodots, we optimized the EBL process using Poly(methyl methacrylate) (PMMA) as an electron beam resist. Metal lift-off was used to transfer the spacing-controlled nanodots as a seed pattern of $TiO_2$ nanowire array. Au or Sn nanodots which play an important role for catalyst using Vapor-Liquid-Solid (VLS) method were patterned on the substrate through the lift-off process. Then, the sample was placed in the tube furnace and heated at the synthesis temperature. After heat treatment, $TiO_2$ nanowire array was fabricated from the nanodots through VLS method (bottom-up). These results of spacing-controlled nanowire arrays will be used to study the interaction between nanostructures and cellular responses in our next steps.

• Proceedings of the KIEE Conference
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.219-221
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• 1999

HVDC(High Voltage Direct Current) transmission system was constructed between Cheju island and mainland Haenam and has been operating commercially since 1998. But research activities in this area are not so much. That is caused by the facts that HVDC is large scale system and it is not so easy to implement and to test. Though such simulation tools as RTDS(Real Time Digital Simulator) and EMTDC can be useful, these have limitations for actual control and protective system design. Therefore scaled-down HVDC model was developed for the purpose of researches at operating technique, control and protection methods. The design of this model was based on real Cheju-Haenam HVDC system. And additionally faults simulator such as ground fault, short-circuit and change of impedance in transmission line is equipped for analysis of these faults. Control system of the model was implemented fully digitally. So it is very easy for the researchers to develope control and protection algorithm and to test the performance.

• Agribusiness and Information Management
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• 제4권1호
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• pp.1-12
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• 2012

Cameroon, with her numerous resources, still depends on foreign aid while the rate of poverty remains high. Thus, even though historical evidence gives impetus to the impasse over role of developmental aid, from the top down approach through to development as a springboard raising states from the doldrums of poverty, it is still very difficult to draw a substantial relationship between developmental aid and poverty reduction. Against this backdrop of controversy, I find it apt to put Cameroon on a balance scale. Therefore, the purpose of this research is to critically assess the implications of developmental aid on poverty reduction and agro-rural development in Cameroon, using the RUMPI Area Development Project in the South West region of Cameroon as a case study. The study will situate and contextualize the top-down and bottom-up approaches to development within the basis of a Cameroonian perspective, using the Sachs-Easterly debate. The RUMPI Project was introduced with the objective of improving agriculture and empowering the rural woman; thereby fighting poverty within the South West region of Cameroon. Despite its criticism of the barriers to development created by corruption, political pressure and limited use of local and grass-root partnerships, the study, in assessing these failures also tries to outline vital ways in which the project can be improved upon.

• Physical Therapy Korea
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• 제17권3호
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• pp.11-19
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• 2010

The purpose of the study was to determine the effects of balance training with 'TETRAX' system, a balance training and assessment tool, on balance and mobility in acute hemiplegic patients. Nineteen matched subjects were assigned randomly into either an experimental group or a control group. An experimental group with 10 subjects received balance training with 'TETRAX' exercise program and conventional physical therapy interventions 5 times per week during 4 weeks. A control group with 9 subjects received conventional physical therapy interventions 5 times per week during 4 weeks. Outcome measures were taken before and after 4 weeks of interventions using the Stroke Rehabilitation Assessment of Movement (STREAM), the Berg Balance Scale (BBS), gait speed, and the fall down index. Results indicated that both exercise groups improved significantly in STREAM, BBS, and gait speed (p<.05). The experimental group had a little improvement than the control group. Both exercise groups did not show statistical significance in fall down index (p<.05). Following 4 weeks of intervention, except gait speed there was no statistically significant difference between two groups. However, these findings suggest that conventional physical therapy interventions with visual feedback training could be effective on improving balance and mobility than conventional physical therapy alone in acute hemiplegic patients.